Both will work with the Tokina 10-17mm. I use the DGX on a D90 and the only difference from the DG is the DGX has
a slight upgrade that allows it to give the correct exif data to some of the newer camera bodies. It was released prior
to the D7000 so I doubt that this nominal benefit will operate on that body. If that is the case then the DG would be
your best and cheaper option. The optics are the same from what I understand.